Four miners were pulled out to safety after they spent more than a month in a collapsed mine nearly 600 feet underground. The rescue event was erringly similar to the rescue operation in Chile when 33 miners were pulled out after being trapped for 69 days underground, including more than two weeks when no one knew whether they were alive.

China has a dismal mine safety world standards, but there have been improvements in the recent years. Mining safety is an emotive issue, and often financial considerations lead to overlooking of safety issues. According to BBC, 931 workers have died in accidents across China in the year 2015.It was a sizeable number though less than the figure in 2002 when it was 7000. The owner of the Shendong mine, Ma Congbo apparently committed suicide by drowning in a well.

The affected mine is located in the eastern province of Shendong, and the collapse had happened on Christmas day last year. The collapse triggered a mini earthquake and registered a magnitude of 4 on the Richter scale. The mine had 30 miners when the explosion happened. One miner was killed immediately, and 29 were trapped deep in the bowels of the earth. 11 were quickly rescued. The rescue team used infrared cameras to locate the starving miners.

Chinese officials originally said that they were looking for eight survivors who were quickly reduced to 4 according to BBC. 13 people are still unaccounted.

The rescue was fraught with danger because of the geology of the area. The soil is rich in gypsum a mineral used to make fertilizer, plaster, and blackboards. It is prone to collapse and sudden spurts of underground water. The surviving miners were ultimately located in intact corridors within the mine. Rescue workers drilled access tunnels and used a capsule to pull out the survivors one by one.